Supporting structures for use in firing pottery

ABSTRACT

A supporting structure for plate-like articles of pottery for use during firing comprising a plurality of vertically spaced cranks of refractory material. The cranks are generally of Vshape in plan and afford a pair of arms having longitudinal center lines coinciding with the shorter sides of an imaginary isosceles triangular (or two adjacent sides of an imaginary regular hexagon). The cranks are spaced apart by spacer blocks which form pillars disposed respectively at the free ends of the arms and at the junction thereof at positions corresponding to the corners of the imaginary isosceles triangle or regular hexagon. The distance between the pillars is such that the platelike article for which the support is intended can just be passed between them and placed on a respective arm. The use of the supporting structure enables the articles to be assembled into a close packed hexagonal array whereby kiln space during firing may be utilized most efficiently.

United States Patent Lovatt [54] SUPPORTING STRUCTURES FOR USE IN FIRING POTTERY [72] Inventor: William John Lovatt, Stoke-on- Trent, England [73] Assignee: Acme Marls Limited, Stafford, En-

gland 22 Filed: March 13, 1970 211 Appl. No.: 19,312

[30] Foreign Application Priority Data March 22, 1969 Great Britain ..l5,157/69 [52] US. Cl ..25/ 153 [51] Int. Cl ..F27d 5/00 [58] Field of Search ..25/153; 263/47, 47 A [56] References Cited UNITED STATES PATENTS 2,006,938 7/1935 Birkenhauer ..249/117 X 1,877,424 9/1932 Fear ..25/153 1,860,374 5/1932 Vincent ..25/153 FOREIGN PATENTS OR APPLICATIONS 1,100,933 1955 France ..249/121 Aug. 8, 1972 1950 Great Britain ..25/153 1909 Great Britain ..25/153 [57] ABSTRACT A supporting structure for plate-like articles of pottery for use during firing comprising a plurality of vertically spaced cranks of refractory material. The cranks are generally of V-shape in plan and atford a pair of arms having longitudinal center lines coinciding with the shorter sides of an imaginary isosceles triangular (or two adjacent sides of an imaginary regular hexagon). The cranks are spaced apart by spacer blocks which form pillars disposed respectively at the free ends of the arms and at the junction thereof at positions corresponding to the corners of the imaginary isosceles triangle or regular hexagon. The distance between the pillars is such that the plate-like article for which the support is intended can just be passed between them and placed on a respective arm. The use of the supporting structure enables the articles to be assembled into a close packed hexagonal array whereby kiln space during firing may be utilized most efficiently.

1 Claim, 3 Drawing Figures SUPPORTING STRUCTURES FOR USE IN FIRING POTTERY BACKGROUND OF THE INVENTION 1. Field of the Invention v This invention relates to supporting structures for use in firing pottery. In particular, the invention is concerned with supporting structures adapted to receive a plurality of plate-like articles, such as saucers, and plates, to enable the latter to be passed through a kiln for firing.

In order to utilize kiln space as efficiently as possible, it is usually necessary to form a stack of such plate-like articles to extend substantially up to the roof of the kiln. Various types of supporting structure are known for this purpose, but all have disadvantages.

2. Description of the Prior Art.

The simplest kind of support for plate-like articles includes three pillars arranged at the corners of an obtuse angle triangle and each carrying a plurality of inwardly directed releasable pins. The plate-like articles are inserted laterally between the pillars and rest at their undersides of the pins. However this inevitably causes small marks to be formed on the underside of the platelike article where it contacts the pins and this is undesirable for high grade ware.

For fine chinaware various supports are known which contact the plate-like article only in the region of the foot of the latter, that is to say an annular downwardly presented ring or flange on which the article normally rests when in use.

One example of such a support structure comprises a plurality of stackable elements each including a central disc-like portion equipped with three equally spaced radially extending legs which at their outer ends are adapted to rest on and interengage with the outer ends of the legs of vertically adjacent elements of similar form. The central disc-like portion of each such element is of such a size that the foot of a plate-like article can be received thereon. Three radially arranged replaceable pins may be provided on the disc-like central portions so that the latter engages the foot of the plate-like article only at three spaced points. However, since the three legs are arranged at equal angular inter vals, the elements have to be assembled together and dis-assembled in order to enable the plate-like articles to be inserted and removed. This is a time consuming process and the frequent handling of the elements can lead to damage. Additionally, each stack of plate-like articles formed on such a support is surrounded by three pillars which are formed from the interengaging end portions of the legs of the elements, and this prevents the plate-like articles being stacked as closely together when viewed from above as is desirable.

A further type of supporting structure which does not require to be assembled and dis-assembled repeatedly to enable the plate-like articles to be inserted and removed, comprises a plurality of vertically spaced generally T-shaped plates (known, and hereinafter referred to as, cranks). These cranks are supported by three pillars at the outer ends of the three arms which form the T-shaped cranks. These arms are so dimensioned that the plate-like articles can be inserted between the two pillars at opposite ends of the two arms of the T-shaped crank which are in alignment with each other, and the length of the third arm is only slightly greater than the radius of the plate-like articles which is intended to be received in the support. Thus the center of gravity of the plate-like articles when supported by such a crank lies very close to the straight line joining the two pillars between which the article is inserted. This results in the loaded supporting structure being rather unstable so that the height of a stack of articles is limited to approximately 1 foot whereas kilns may accept loads up to 3 feet or more in height. Accordingly to fill' the kiln completely it is necessary to form several layers of such supports on respective base plates which are supported and spaced by upright posts. This additional supporting structure, however, takes up a significant amount of kiln space and also represents a wasteful thermal loading of the kiln.

As an alternative to these types of supporting structure, it has been proposed to adopt a compromise arrangement in which the cranks are of generally Y- shape having two of the arms thereof arranged at an angle of approximately instead of 120 or as in the previous described arrangements.

Nevertheless such a supporting structure still prevents the stacks of plate-like articles being arranged in the theoretically closest possible packing arrangement within the kiln, and moreover it is in practice difficult to insert the plate-like articles into position on the cranks without dis-assembling the cranks and stacking them simultaneously with insertion of the plate-like articles.

It will be understood that the theoretically closest possible packing arrangement of stacks of generally circular plate-like articles consists of a close packed regular hexagonal array in which each stack of articles is surrounded by six equidistant stacks the center of which lie at the corners of a regular hexagon centered on the central stack. in the theoretical arrangement for closest possible packing, each stack of articles would actually touch its six nearest neighbors, but to prevent the articles sticking to one another it is necessary to ensure that the stacks are spaced apart slightly. Thus the free space within the kiln consists of a plurality of generally triangular areas each bounded by three stacks of articles with their centers arranged at the corners of an equilateral triangle of which the sides are only slightly longer than the diameter of the articles. Such an arrangement will hereinafter be referred to as a close packed hexagonal array.

SUMMARY OF THE INVENTION The object of the present invention is to provide a new or improved supporting structure for plate-like articles of pottery for use during firing in which the above mentioned disadvantages are avoided or at least reduced.

According to the first aspect of the present invention a supporting structure for plate-like articles of pottery for use during firing, comprises a plurality of vertically spaced cranks of refractory material and pillars supporting the cranks so that the structure can be supported on a flat surface. Each of said cranks is adapted to receive at least two of said plate-like articles and said cranks are so shaped, and the pillars so disposed relative to each other and said plate-like articles when placed on said cranks, that a plurality of such supporting structures with said plate-like articles thereon can be arranged to form said articles into a close packed hexagonal array with said articles spaced apart slightly at their peripheries and with said pillars of said supporting structures disposed in respective generally triangw lar spaces each by groups of three adjacent stacks of said articles.

In a preferred embodiment the supporting structure includes three of such pillars arranged at three adjacent corners of a regular hexagon.

The distance between adjacent pillars may be slightly greater than the diameter of the articles to be carried thereby so that the latter can be inserted laterally between such pillars.

Said pillars preferably are disposed at positions corresponding to the corners of an obtuse angle isosceles triangle of which the shorter sides have a length which is greater than the diameter of said plate-like articles to be supported by the crank by only the extent necessary to enable said plate-like articles to be positioned on the cranks by lateral insertion between those pillars which are disposed at opposite ends of the respective shorter sides of the triangle.

Each crank may be shaped to afford two arms having longitudinal center lines which coincide with the shorter sides of said triangle and are each adapted to receive a single one of said plate-like articles thereon, one of said pillars being disposed at the junction of such arms and the remaining two of said pillars being disposed at the ends of the respective arms. In an alternative arrangement each crank could include three arms each adapted to receive one article, with the pi]- lars disposed at the outer ends of the respective arms.

Each of the arms may be provided with a set of pins arranged to support the foot of an article to be supported. Such pins may be replaceable.

Preferably the cranks are of generally flat form, and conveniently the pillars are formed as spacers between respective cranks. Preferably the cranks and spacers are bonded together to form a permanent structure.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described by way of example with reference to the accompanying drawings wherein:

FIG. 1 shows a supporting structure in accordance with the invention in a perspective view,

FIG. 2 shows a horizontal section taken between a pair of cranks, and

FIG. 3 is a diagram of the hexagonal close packing arrangement which can be employed.

DESCRIPTION OF THE PREFERRED EMBODIMENT The supporting structure illustrated includes a plurality of cranks stacked in vertically spaced relation by means of three sets of spacer members 11, 12 and 13. Each crank 10 comprises a flat plate of high grade refractory material and includes a central parallel sided portion 14 and two arm portions 15 which taper in width towards their outer ends. The arms are inclined towards each other at an angle of approximately 120 as defined by their longitudinal center lines 150. The spacer members each comprise rectangular blocks of high grade refractory material. The spacer members 11 and 12 disposed at the free ends of the arms 15, while the spacer members 13 are located adjacent to one edge of the central portions 14 at the junction of the two arms as defined by the intersection of their center lines. Thus it will be seen that the pillars are arranged at the comers of an isosceles triangle (or three adjacent corners of a regular hexagon.

The distance between spacer members 11 and 13, and 12 and 13 is made slightly greater than the diameter of the plate-like articles to be carried by the support. The position of such plate-like articles is shown at 16 in FIG. 2. The pillars defined by the columns of spacer members are located in such manner that a plurality of the supporting structures can be located in a kiln in such a manner that the stacks of articles carried thereby are arranged in a close packed hexagonal array as shown in FIG. 3 with the pillars disposed in respective areas which correspond to generally triangular spaces between such stacks of articles. In particular it is to be noted that there are three such pillars associated with a pair of stacks of articles, and when such articles are arranged in a close packed hexagonal array the pillars will be disposed in the generally triangular spaces which are bounded by three adjacent stacks, and there will be only one such pillar in each such space. This is illustrated in more detail in FIG. 2 wherein the positions of adjacent stacks of articles are indicated by the reference numeral 17. As can be seen there are 10 such spaces 8 -8 adjacent to the twostacks of articles indicated at 16, and only three of these spaces (S S S,,) are occupied by the pillars formed by the spacer members l l, 13 and 12 respectively. The remaining triangular spaces are therefore available for the pillars of other supporting structures and and the close packed hexagonal array can be assembled without difficulty in the manner indicated in FIG. 3 in which the position of the stacks of plate-like articles are represented by circles A and the cranks are represented by V-shaped markings C corresponding to the center lines 15a of their arms, with the pillars shown as dots P.

It will thus be apparent that none of the triangular spaces is required to contain more than one pillar. Accordingly, the spacings between adjacent stacks of articles can be kept to a minimum. This results directly from the fact that the pillars are arranged at the corners of an isosceles triangle having an apex angle of approximately or, stated in an alternative way at three adjacent corners of a regular hexagon.

It will be understood that if it were necessary to accommodate two such pillars in some spaces, the spacing between adjacent stacks would have to be increased in order to enlarge the triangular spaces to make room from two such pillars of sufficient cross-sectional dimensions to bear the weight of the loads imposed. This would represent a waste of kiln space and is avoided by the present invention.

The use of the supporting structure as described therefore enables the plate-like articles to be stacked in a kiln in the most preferential manner as regards the number of articles that can be accommodated within any given area.

It is preferred for the supporting structure to include only three pillars since the arrangement of three point contact with a supporting surface will ensure that the structure will stand evenly on such surface despite irregularities in the latter, whereas the provision of four or more pillars could lead to uneven loading of the supporting structure with the possibility of fracture of the cranks. However, in an alternative design it would be possible for the cranks to be of a. three armed form with the arms arranged at equal angles. In this case the spacer members would be arranged only at the outer ends of the arms and the articles could still be assembled in a close packed hexagonal array with no more than one pillar in any of the generally triangular spaces.

To support the articles on the cranks, a respective set of pins is provided on each arm. Each set includes three pins 18 which are disposed at angles of approximately 120 to each other to provide a stable support for the foot of a plate-like article. These pins may be replaceably located in shallow grooves formed in the cranks, and one end of each pin may be of rounded form to enable an article to be inserted laterally with little risk of damage. However preferably such rounded portion is afforded by a small projection formed in the crank at one end of the recess which receives the pin. This arrangement is particularly suitable for the second firing of china or like articles after glazing, the layer of glaze being removed from the foot of the article before it is placed on the supporting structure. However, alternatively the pins may be omitted entirely so that the articles stand on the flat upper surface of the crank directly. In this case the supporting structure may be used for a single firing technique in which the articles are coated with a glaze before firing, and are fired only once.

It will be appreciated that the shape of the crank can be modified in various ways providing they do not protrude into the areas which are required to accommodate the pillars of the supporting structures when the articles are arranged in the close packed hexagonal array. However, the shape described and illustrated is particularly convenient since it affords a zone at the inner end of the arms of a suitable width to accommodate the foot of a plate-like article of the size for which the support is intended while unnecessary weight is avoided by tapering the arms towards their outer ends. However, it would of course be possible to make the cranks of a curved shape decreasing in width from the central portion of the outer ends thereof, or the cranks could be of generally rectangular or bar-like form with one pillar disposed mid-way along one of the longer sides and two further pillars disposed at opposite ends of the other longer side.

Iclaim:

1. A support assembly for use in supporting plate-like articles of pottery during firing, the support assembly comprising a plurality of supporting structures; each supporting structure comprising a plurality of vertically spaced cranks of refractory material and pillars supporting the cranks, each of said cranks having two arm portions, each arm portion including support means for a respective plate-like article and the arm portions of each crank being angularly disposed relative to each other so as to define two adjacent sides of a regular hexagon and each of the cranks being supported by three pillars at spaced positions; the supporting structures being arranged relative to each other so as to place the support means for the plate-like articles in a hexa onal array and, to dis se inch pillar o the su portr g structures in a ggner y rranguar spa e bounded by three adjacent support means to enable plate-like articles supported by support means to assume a hexagonal close packed array. 

1. A support assembly for use in supporting plate-like articles of pottery during firing, the support assembly comprising a plurality of supporting structures; each supporting structure comprising a plurality of vertically spaced cranks of refractory material and pillars supporting the cranks, each of said cranks having two arm portions, each arm portion including support means for a respective plate-like article and the arm portions of each crank being angularly disposed relative to each other so as to define two adjacent sides of a regular hexagon and each of the cranks being supported by three pillars at spaced positions; the supporting structures being arranged relative to each other so as to place the support means for the plate-like articles in a hexagonal array and to dispose each pillar of the supporting structures in a generally triangular space bounded by three adjacent support means to enable plate-like articles supported by support means to assume a hexagonal close packed array. 